Black Monks :
I guess I'm a vertical thinker and not a lateral thinker.  I know how to get more than the banks hold.  I know that you can pay real cash for more cash.  The thought of 600 million still baffles my mind.  I for one have no clue how it happened, if it happened.  
You've answered the question Monks. Whilst anyone can store more money than their banks hold, realistically a figure of 600m is only achievable by using gold balls.